Refrigerator cabinet construction



Dec. 23, 1952 H. w. EAGLES REFRIGERATOR CABINET CONSTRUCTION Filed April25, 1948 Inventor 4 HoracewEagles His Attorney.

Patented Dec. 23, 1952 UNITED STATES PATENT OFFICE 2,622,754REFRIGERATOR CABINET CONSTRUCTION Horace W. Eagles, Erie, Pa., assignorto General Electric Company, a corporation of New York Application April23, 1948, Serial No. 22,869

13 Claims.

My invention relates to refrigerated cabinets and more particularly toarrangements for insulating such cabinets.

In the construction of refrigerated cabinets, and particularly ofhousehold freezers wherein a low temperature must be maintained, it isdesirable to employ a material with good thermalinsulating properties soas to be able to minimize the thickness of insulation required.Reduction in the thickness of insulation is, of course, refiected inincreased space available within the freezer for the storage of frozenfoods without any increase in the space required by the cabinet. Somematerials having desirable heat-insulating characteristics have anundesirable characteristic of limited settling due to jarring orvibration during factory handling and shipment and during operation ofthe cabinet, with the resultant appearance of voids within theinsulation. The above characteristics are exhibited for example, byheat-insulating materials of the aerogel type, including inorganicaerogels, such as, silica aerogel, alumina aerogel, etc., organicaerogels, such as, organosilicon aerogel, described and claimed in theapplication of John R. Elliott and Robert H. Krieble, Serial No.577,343, filed February 10, 1945, now Patent No.

2,441,423, and assigned to the same assignee as the present invention,and organic-inorganic aerogels, such as, organo-silicon-silica aerogels,described and claimed in the application of Robert H. Krieble and JohnR. Elliott, Serial No. 577,342, filed February 10, 1945, now Patent No.2,441,422, and assigned to the same assignee as the present invention.The presence of such voids adversely affects the insulating properties.Also, the insulating properties of the inorganic aerogels may beadversely affected by condensation of moisture thereon in the insulationspace, because of resultant shrinkage of the material involved.

It is an object of my invention to provide an improved arrangement forinsulating a refrigerated cabinet.

7 It is another object of my invention to provide a refrigerated cabinetconstruction including an improved arrangement for minimizing voids inthe insulation.

. It is a further object of my invention to provide a refrigeratedcabinet construction including an improved arrangement for minimizingtransmission of moisture into the insulation space.

Other objects and advantages of my invention will become apparent as thefollowing descrip- 2 tion proceeds and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming part of this specification.

For a better understanding of my invention reference may be had to theaccompanying drawing in which Fig. 1 is a rear elevation view of arefrigerator cabinet incorporating my invention; Fig. 2 is an enlargedview of a portion of the cabinet shown in Fig. 1; Fig. 3 is a rearelevation view of the cabinet in an inverted position; Fig. 4 isanenlarged view of a portion of the cabinet illustrated in Fig. 3; andFig. 5 is an enlarged view of a portion of the cabinet showing theelements in a slightly diiierent position.

Referring now to the drawing, there is shown a refrigerated cabinet 1 ofthe chest type suitable for the storage of frozen foods. The cabinetincludes an outer wall 2 and an inner wall 3, the inner wall forming acompartment 4 for food storage. The compartment 4 is provided with anaccess opening at the top and this opening is closed by a lid 5. At thebottom of the cabinet a machinery compartment 6 is provided for housingthe refrigerant condensing apparatus (not shown).

A breaker strip 1 of suitable heat-insulating material is provided forclosing the space between the inner and outer walls adjacent the accessopening of the cabinet. The breaker strip is secured to the walls 2 and3 respectively by screws 8, 9 or other suitable fastening devices. Agasket Iii is provided between the lid 5 and the outer wall 2 forsealing the storage space. The gasket is clamped between the breakerstrip and the outer wall by the screw 8.

The space between the walls 2 and 3 is adapted to be filled with aheat-insulating material I l of the aerogel type, for example, silicaaerogel. This material may be subject to settling due to jarring orvibration during handling or operation of the cabinet. Hence, voids mayform, particularly in the upper portion of the insulating space betweenthe walls 2 and 3, and thereby reduce the insulating effect. In order tominimize such voids a construction including a flexible diaphragm I2 isemployed within the space between the walls 2 and 3 in the general areaof the breaker strip 1. This diaphragm is formed of a flexible,moisture-impervious material, such as rubber. One edge of the diaphragmis held between a retaining strip l3 and the outer Wall 2 bya screw M orother suitable fastening device. The other edge of the diaphragm issimilarly held between a retaining strip 15 and the inner wall 3 by ascrew It or other suitable fastening device. The diaphragm is preferablycemented to these walls to insure sealing engagement therewith.

During the process of introducing heat-insulating material into thespace between the walls 2 and 3, the cabinet is first placed in theinverted position shown in Fig. 3. The rear wall of the cabinet includestwo filling openings I! and I8 adjacent a bottom portion I9 of the outerwall 2. The heat-insulating material II is introduced into the spacebetween the inner and outer walls through the filling opening I1. Thisis accomplished by blowing, pouring or vibrating the insulation intothis opening, the air being vented through the opening I8. A suitablefilter bag,

may be placed across the opening I8 to allow the exhausting of the airtherethrough without permitting the passage of the heat-insulatingmaterial therethrough. The space between the inner and outer walls isfilled with the heat-insulating material during this operation. Thecabinet may be tipped forward toward the end of the filling operation soas to insure that the filling hole I! is at the highest point in thespace to be filled. As shown most clearly in Fig. 4, the flexiblediaphragm I2 is forced toward the breaker strip during this operationminimizing the space between the breaker strip and the flexiblediaphragm.

When the filling with the heat-insulating material II has been completedthe holes I1 and I8 are closed by suitable caps 2| and 22. These capsmay be welded or otherwise secured to the outer wall 2 to seal theseopenings. The cabinet is then placed in the upright position illustratedin Fig. 1. The breaker strip I is removed and resilient compressibleheat-insulating material 23, such as spun glass, wood fiber, felt, etc.i placed within the space 20. An excess of heat-insulating material 23is employed, that is, an amount which is of greater volume beforecompression than the space 20 between the diaphragm I2 and the normalposition of the breaker strip 1. The breaker strip 1 is then replaced,compressing the heat-insulating material 23 and forcing the diaphragm I2into the general shape illustrated in Fig. 2.

It will be observed that the space 20 between the diaphragm and thebreaker strip in Fig. 2 is less than the maximum space available betweenthe diaphragm and the breaker strip, as illustrated in Fig. 5. Thus theheat-insulating material 23 in Fig. 2 is compressed between the breakerstrip I and the mass of heat-insulating material I I. During handling ofthe cabinet and during operation of the refrigerating apparatus theheat-insulating material I I may settle to some extent. As it does so,the compressed resilient heat-insulating material 23 expands to maintainthe diaphragm I2 against the mass of heat-insulating material II, andthereby fill any voids which might otherwise be left by the recedingheat-insulating material I I.

It should be noted particularly that the resilient compressibleheat-insulating material 23 is arranged in the region adjacent thebreaker strip I. The area in the region of the access opening of thecabinet and of the breaker strip I is particularly susceptible to thecondensation of water vapor or sweating, and this condition isaggravated by any voids which might appear in the area adjacent thebreaker strip. The arrangement disclosed above, by providing thecompressible heat-insulating material in this particular region,specifically insures the presence of heat-insulating material in thisarea.

Where the heat-insulating material II employed is an aerogel of theinorganic type, it may be adversely affected by moisture, and hence itis desirable to minimize the transmission of moisture into theinsulation space between the walls 2 and 3. While the walls of thecabinet may be securely Welded to prevent such leakage of moisture,moisture may leak into the insulation space in the region around thebreaker strip I. The flexible diaphragm minimizes such leakage ofmoisture in this region, since the diaphragm is made of amoisture-impervious material, such as rubber, and is arranged alongthose portions of the cabinet where leakage might otherwise occur.

In describing the process of insulating the cabinet the heat-insulatingmaterial I I has been de scribed as being introduced into the cabinetbefore any heat-insulating material is placed in the space 20 betweenthe diaphragm and the breaker strip. If desired, the resilientcompressible heat-insulating material 23 may be first placed in thespace 20, forcing the diaphragm I2 to the general shape shown in Fig. 5.The cabinet may then be inverted as shown in Fig. 3 and theheat-insulating material II introduced as before. The mass of theheat-insulating material II compresses the heat-insulating material 23to the general shape shown in Fig. 2. Any subsequent settling of theheat-insulating material II results in an expansion of theheat-insulating material 23 toward the shape shown in Fig. 5, aspreviously described.

In the insulating arrangement previously described the breaker strip Iwas set forth as secured in position before the cabinet was inverted andthe heat-insulating material II introduced. When the cabinet was shiftedto the position shown in Fig. 1 it was necessary to remove the breakerstrip, introduce the heat-insulating material 23, and then replace thebreaker strip. The original assembly of the breaker strip is requiredbecause in the particular cabinet construction illustrated, the breakerstrip constitutes the support holding the inner and outer walls inspaced relationship. It will be apparent, therefore, that should a formof cabinet construction be employed in which other elements are utilizedfor holding the Walls in spaced relationship, the breaker strip need notbe installed until after the heat-insulating material II has beenintroduced and the resilient compressible heat-insulating material 23has been placed in the space 20.

While I have shown and described a specific embodiment of my invention,I do not desire my invention to be limited to the particularconstruction shown and I intend by the appended claims to cover allmodifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A refrigerated cabinet comprising an outer wall, an inner wall spacedfrom said outer wall, a breaker strip closing the space between saidwalls, a moisture-impervious, flexible diaphragm engaging said wallsadjacent said breaker strip and extending into the space between saidwalls, a heat-insulating material filling the space between said walls,and a resilient compressed heat-insulating material filling the spacebetween said breaker strip and said diaphragm and exerting pressure onsaid diaphragm.

2. A refrigerated cabinet comprising an outer wall, an inner wall spacedfrom said outer wall, a breaker strip closing the space between saidwalls, a moisture-impervious, flexible diaphragm, a retaining stripmaintaining one edge of said diaphragm in engagement with said outerwall, a second retaining strip maintaining another edge of saiddiaphragm in engagement with said inner wall, said diaphragm beingspaced from said breaker strip and extending into the space between saidwalls, a heat-insulating material filling the space between said walls,and a resilient compressed heat-insulating material filling the spacebetween said breaker strip and said diaphragm and exerting pressure onsaid diaphragm. 3. A refrigerated cabinet comprising an outer wall, aninner wall spaced from said outer wall, a breaker strip closing thespace between said walls, a moisture-impervious, flexible diaphragmengaging said walls adjacent said breaker strip and extending into thespace between said walls, a heat-insulating material of the aerogel typefilling the space between said walls, and aresilient compressedheat-insulating material filling the space between said breaker stripand said diaphragm.

4. A refrigerated cabinet comprising an outer wall, an inner wall spacedfrom said outer wall, a breaker strip closing the space between saidwalls, a moisture-impervious, flexible diaphragm engaging said Wallsadjacent said breaker strip and extending into the space between saidwalls, a heat-insulating material filling the space between said. walls,said material being of a type subject to settling due to vibrationduring handling and operation of the cabinet, and a resilient compressedheat-insulating material filling the space between said breaker stripand said diaphragm, said last-named heat-insulating material expandingto fill any voids resulting from settling of said flrstmamedheat-insulatin material.

5. A refrigerated cabinet comprisin an outer wall, an inner wall spacedfrom said outer wall, said walls being formed to provide an accessopening at the top of said cabinet, 3, breaker strip closing the spacebetween said wall adjacent said access opening, a moisture-impervious,flexible diaphragm secured to said walls adjacent said breaker strip,said diaphragm being spaced from said strip and extending into the spacebetween said walls, a heat-insulating material of the aerogel typefilling the space between said walls, and a resilient compressibleheat-insulating material filling the space between said diaphragm andsaid breaker strip, said last-named heat-insulating material beingplaced in said last-named space under compression and having thecharacteristic of expanding to fill any voids resulting from thesettling of said first-mentioned heat-insulating material.

6. A refrigerated cabinet comprising an outer wall, an inner wall spacedfrom said outer wall, a breaker strip closing the space between saidwalls, a moisture-impervious, flexible diaphragm, a retaining stripmaintaining one edge of said diaphragm in engagement with said outerwall, a second retaining strip maintaining another edge of saiddiaphragm in engagement with said inner wall, said diaphragm beingspaced from said breaker strip and extending into the space between saidwalls, a heat-insulating material of the aerogel type filling the spacebetween said walls, and a resilient compressed heat-insulating materialfilling the space between said breaker strip and said diaphragm, saidlast-mentioned heat-insulating material tending to expand and 6. therebyincrease the extension of said diaphragm into said space between saidwalls.

'7. In the assembly of a refrigerated cabinet including spaced inner andouter walls, a breaker strip for closing the space between said walls,and a moisture-impervious, flexible diaphragm secured to the Wallsadjacent the breaker strip and spaced from the breaker strip in theassembled position of the breaker strip, the method of insulating thecabinet which comprises filling the space between the walls withheat-insulating material, placing an excess of a resilient compresssibleheat-insulating material adjacent said diaphragm on the breaker stripside thereof, placing said breaker strip against said resilientheatinsulating material, pressing said breaker strip into engagementwith the walls of said cabinet to compress said resilientheat-insulating material and cause said resilient heat-insulatingmaterial to exert pressure on said diaphragm, and securing said breakerstrip in position in engagement with said walls.

8. In the assembly of a refrigerated cabinet including spaced inner andouter walls formed to provide an access opening for the cabinet, abreaker strip for closing the space between the Wa11s adjacent theaccess opening, and a moisture-impervious, flexible diaphragm engagingthe walls adjacent the breaker strip and spaced from the breaker stripin the assembled position of the breaker strip, the method of insulatingthe cabinet which comprises arranging the cabinet with the accessopening downward, filling the space between said walls withheat-insulating material,

arranging the cabinet with the access opening upward, placing an excessof a resilient compressible heat-insulating material adjacent saiddiaphragm on the breaker strip side thereof, placing said breaker striagainst said resilient heatinsulating material, pressin said breakerstrip into engagement with the walls of said cabinet to compress saidresilient heat-insulating material and cause said resilientheat-insulating material to exert pressure on said diaphragm, andsecuring said breaker strip in position in engagement with said walls.

9. In the assembly of a refrigerated cabinet including spaced inner andouter walls, a breaker strip for closing the space between said walls,and a moisture-impervious, flexible diaphragm secured to the wallsadjacent the breaker strip and spaced from the breaker strip in theassembled position of the breaker strip, the method of insulating thecabinet which comprises filling the space between the walls with aheat-insulating material of the aerogel type, placing an excess of aresilient compressible heat-insulatin material adjacent said diaphragmon the breaker strip side thereof, placing said breaker strip againstsaid resilient heat-insulating material, pressing said breaker stripinto engagement with the walls of said cabinet to compress saidresilient heatinsulating material and cause said resilientheatinsulating material to exert pressure on said diaphragm, andsecuring said breaker strip in position in engagement With said walls.

10. In the assembly of a refrigerated cabinet including spaced inner andouter walls, a breaker strip for closing the space between said walls,and a moisture-impervious, flexible diaphragm engaging the wallsadjacent the breaker strip and spaced from the breaker strip in theassembled position of the breaker strip, the method of insulating thecabinet which comprises filling the space between the walls with aheat-insulating material of theaerogel type, removing the breaker strip,placing an excess of a resilient compressible heat-insulating materialadjacent said diaphragm on the breaker strip side thereof, and replacingthe breaker strip to compress said resilient heat-insulating materialand cause said resilient heat-insulating material to exert pressure onsaid diaphragm.

11. In the assembly of a refrigerated cabinet including spaced inner andouter walls, a breaker strip for closing the space between said walls,and a moisture-impervious, flexible diaphragm secured to the wallsadjacent the breaker strip and spaced from the breaker strip in theassembled position'of the breaker strip, the method of insulating thecabinet which comprises filling the space between the diaphragmand theplane occupied by the breaker strip in the assembled position of saidbreaker strip with a resilient compressible heat-insulating material,closing said space with said breaker strip, and filling the spacebetween said walls with a heat-insulating material of the aerogel typesufiicient in amount to compress said first-mentioned heat-insulatingmaterial.

12. In the assembly of a refrigerated cabinet including spaced inner andouter walls formed to provide an access opening for the cabinet, abreaker strip for closing the space between the walls adjacent theaccess opening, and a moisture-impervious, flexible diaphragm engagingthe walls adjacent the breaker strip and spaced from the breaker stripin the assembled position of the breaker strip, the method of insulatingthe cabinet which comprises arranging the cabinet with the accessopening downward, filling the space between the walls with aheat-insulating material of the aerogel type, arranging the cabinet withthe access opening upward, placing an excess of a resilient compressibleheat-insulating material adjacent said diaphragm on the breaker stripside thereof, placing said breaker strip against said resilientheat-insulating material, pressing said breaker strip into engagementwith the walls of said cabinet to compress said resilientheat-insulating material andcause said resilient heat-insulatingmaterial .to exert pressure on said diaphragm, and securing said breakerstrip in positionin engagement with said walls.

13. In the assembly of a refrigerated cabinet including spaced inner andouter walls formed to provide an access opening for the cabinet, a.breaker strip for closing the space betweensaid walls adjacent theaccess opening, and a moisture-impervious, flexible diaphragm secured tothe walls adjacent the breaker strip and spaced from the breaker stripin the assembled position of the breaker strip, the method of insulatingthe cabinet which comprises arranging the cabinet with the accessopening downward, filling the space between the walls with aheat-insulating material of the aerogel type, arranging the cabinet withsaid access opening upward, removing said breaker strip, placing anexcess of a resilient compressible heat-insulating material adjacentsaid diaphragm on the breaker strip side thereof, and replacingsaidibreaker strip to compress said last-named heat-insulating materialand cause said resilient heat-insulating material to exert pressure onsaid diaphragm.

HORACE W. EAGLES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

